1. Field of the Invention
The present invention relates to a method and apparatus for searching human three-dimensional (3D) posture, and more particularly, the present invention relates to a method and apparatus for searching a human 3D posture which can extract posture descriptors from respective postures of human 3D models using relation among respective joints, and rapidly and accurately search a human 3D posture database using the posture descriptors.
2. Description of the Related Art
Recently, data searches have been performed mainly by a language-based search. However, with the recent development of the multimedia technique and the explosive growth of the Internet, a massive amount of multimedia data exists on Internet or in multimedia databases, and the development of methods of effectively searching multimedia data among multimedia data composed of a movie, synthetic image, still image, moving image, audio, music, etc., in addition to language is in progress.
Among the recent data searching methods, a method of searching a still image or moving image has been actively researched in accordance with the appearance of a virtual reality represented by the computer graphic technique and the development of the digital image compression technique based on the object-oriented coding technique. Especially, with the development of the computer and image processing technique, human 3D models in a virtual space have been diversely used for a realistic movie, game, advertisement, virtual circumstance on a network, etc., and thus the search of the human 3D posture is an important factor for the image search.
Since the human 3D posture data has a large amount of data and exists in diverse forms, it is impossible to search a desired 3D posture using the human 3D posture itself.
Accordingly, in order to search the human 3D posture, the search should be performed in a manner that a posture database is established by extracting features representing respective postures by pre-processing, and then the similarity is compared between the posture and a query 3D posture whose feature is extracted in the same manner. The comparison of the similarity can be performed by calculating the difference between the postures. The model representing the feature of the human 3D posture is called a posture descriptor.
As the posture descriptor representing the feature of the 3D image data generally used, there exist volume information for representing how wide 3D points are distributed in space, and histogram information for representing position information of the points as several divided groups. Such information, however, is not suitable for representing the human 3D posture by the feature for representing a general 3D model.
The most accurate method of representing the human 3D model represents the posture with point information constituting respective parts of a body, surface information for the respective points connected one another, and color information of the surface. According to this method, the amount of data for representing the human 3D posture becomes excessively large. If the amount of data becomes large, lots of storage space are required when the human 3D model data is processed on the computer, and it takes a long time for search, so that a rapid and effective search cannot be effected. Thus, in order to make an effective multimedia search possible, the development of an effective human 3D posture searching method is strongly required.
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a method and apparatus for searching a human 3D posture which enables a rapid and accurate database search by effectively representing the human 3D posture with a small amount of data.
It is another object of the present invention to provide a method and apparatus for searching a human 3D posture which can obtain a faithful search result in spite of the difference among human body shapes by using position information of the respective parts of the body applied to a standard body model.
In order to achieve the above objects, according to the present invention, there is provided a method of searching a human three-dimensional (3D) posture, comprising a posture descriptor extracting step of extracting a posture descriptor from a human query 3D posture using relation among respective joints of a human body, an other posture descriptor extracting step of extracting posture descriptors of human 3D models in a posture database in the same manner as the posture descriptor extracting step, a database establishing step of establishing the posture database with the posture descriptors of the human 3D models extracted at the previous step, a 3D model database establishing step of establishing a 3D model database using the human 3D models, a similarity comparing step of comparing an output query posture descriptor with the posture descriptors in the posture database, and a comparison result outputting step of outputting the 3D model database corresponding to the posture having the highest similarity in the posture database by indexing the similarity in accordance with a result of the similarity comparison at the previous step.
According to another aspect of the present invention, there is provided a method and apparatus for searching a human 3D posture using body animation parameters (BAP) that use rotating angles among neighboring joints connected one another in a 3D body as posture descriptors, or using BAP posture descriptors of a standard body model obtained by applying the BAP posture descriptors to the standard body model.